The ultimate goal of ZSL is to predict unseen classes. There are many similar attributes between seen and unseen classes, but they often contain different appearances (such as tails. Pig tails are very different in appearance compared to tigers, zebras and other animals), which may lead to the problem of domain shift[1]}, so that when the model recognizes the unseen class, it is often classified into the seen class, resulting in a decrease in model accuracy.
